APF is the abbreviation of Advanced Policy Firewall. It is a policy based firewall system designed to configure firewall (IPTables rules) simply and user friendly. Configuring iptables is slightly hard without the help of an application like APF or CSF. We have already discussed a lot of topics regarding the firewall system CSF. Here I am explaining the steps to install APF in a Linux based server/system. RPM and tar.gz format installation packages are available. How to install and configure APF(Advanced Policy Firewall) in Linux based server?